气候变化领域集成服务门户(CCPortal): Paleomagnetism of Middle Triassic Lavas From Northern Qiangtang (Tibet): Constraints on the Closure of the Paleo-Tethys Ocean

CCPortal

DOI	10.1029/2019JB017804
	Paleomagnetism of Middle Triassic Lavas From Northern Qiangtang (Tibet): Constraints on the Closure of the Paleo-Tethys Ocean
	Song P.; Ding L.; Lippert P.C.; Li Z.; Zhang L.; Xie J.
发表日期	2020
ISSN	21699313
卷号	125 期号:2
英文摘要	We present results from a paleomagnetic study of Middle Triassic lavas (~242–240 Ma) from the northern Qiangtang block to improve our understanding of the timing and kinematics of the closure of the eastern Paleo-Tethys Ocean. Characteristic remanent magnetization directions carried by magnetite and hematite formed during high-temperature oxidation during initial cooling of the lavas are successfully isolated by progressive thermal and alternating field demagnetizations. We bin 28 site mean directions into 20 independent direction groups that pass the fold test, average secular variation, and show no rock magnetic or petrographic evidence of weathering. These data establish the first lava-based paleomagnetic pole of Middle Triassic age for the northern Qiangtang block (62.2°N, 196.4°E, A95 = 5.6°). We compare this pole to coeval poles from the North China Block and Tarim and estimate that the remnant Paleo-Tethys or Hoh-Xil-Songpan-Ganzi Ocean could have been up to 700 km at ~240 Ma. A comparison of the Triassic latitudinal history between the northern Qiangtang block and the North China Block and Tarim shows that the closure of the Paleo-Tethys Ocean most likely occurred during the latest Triassic. Our review of published Permian-Triassic poles from the northern Qiangtang block show that the average south-north plate velocity of the terrane decelerated from ~8.5 cm/yr during ~300–240 Ma to ~3.6 cm/yr during ~240–210 Ma. We suggest that an arc-continent collision between the northern Qiangtang block and a Paleo-Tethys or Yidun arc around or before 240 Ma contributed to this change in plate velocity. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Middle Triassic lavas; Northern Qiangtang; Paleomagnetism; The closure of the Paleo-Tethys Ocean; Tibet
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187938
作者单位	Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China; Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, United States; Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, China
推荐引用方式 GB/T 7714	Song P.,Ding L.,Lippert P.C.,et al. Paleomagnetism of Middle Triassic Lavas From Northern Qiangtang (Tibet): Constraints on the Closure of the Paleo-Tethys Ocean[J],2020,125(2).
APA	Song P.,Ding L.,Lippert P.C.,Li Z.,Zhang L.,&Xie J..(2020).Paleomagnetism of Middle Triassic Lavas From Northern Qiangtang (Tibet): Constraints on the Closure of the Paleo-Tethys Ocean.Journal of Geophysical Research: Solid Earth,125(2).
MLA	Song P.,et al."Paleomagnetism of Middle Triassic Lavas From Northern Qiangtang (Tibet): Constraints on the Closure of the Paleo-Tethys Ocean".Journal of Geophysical Research: Solid Earth 125.2(2020).